Silo unloader



Sept. 8, 1953 w. R. PETERSON SILO UNLOADER 4 Sheets-Sheet 1 Filed Nov. 28, 1947 lrweni or Malia 71B. Peale ns'on Sept. 8, 1953 w. R. PETERSON SILO UNLOADER 4 Sheets-Sheet 2 Filed Nov. 28, 1947 Sept. 8, 1953 w. R. PETERSON 2,551,438

SILO UNLOADER Filed Nov. 28, 1947 4 Sheets-Sheet 3 [I II II '[I II II II II [I II j 120605 walk/J5. fd'erson P 8, 1953 w. R. PETERSON 2,651,438

SILO UNLOADER Filed Nov. 28, 19 47 iSheaeizs-sheer. 4

w Q Q Q 1 R? Q R1 F o F w a m N]- Qj uluuuuu g g g Q G) 7 V E S J t\/w- Q} 00 31 T w W *1 H Q a g 1 Patented Sept. 8, 1953 SILOUNLOADER Walterlt Petersom Hinsdale; -Ill., assignor to --InternationalHarvester Company, a corporation oLNew-Ierscy Application November-28, 1947, Serial No. 788,528

This invention relates to an ensilage'unloading mechanism for unloading a silo and more -particularly to a self-propelled: ensilage unloader. Specifically, this invention relates to an improved silo unloading structure, said' structure being constructed to be supported on the top surface'of a quantity of packed ensilage within a vertical silo.

The removal of ensilage from a vertical silo has been one of the great time consuming chores on a farm. It has been the necessary task of a farm operator to climb' the tedious and dangerous ladder which is usually connected to the outer surface of the wall of a silo. After'climbing to the top of the silo, the farmer "usually had to manually remove the ven ilage with a pitch fork or shovel. Various mechanical devices have been designed with the apparent; intention to overcome this problem, but until applicants invention no practical and inexpensive designs had emerged. In order to provide an eflfective and inexpensive ensilage unloader, applicant has designed a novel mechanism which has for its prime object the removal of "ensilage in an eflicient, effective, and entirely mechanical manner.

An important object of the'invention is to provide a silo unloader that is supported on the top surface of packed. ensilage within the silo,

{said unloader including a'wheeledframe rotatable circumferentially'within a cylindrical vertical silo. J

Another object is to provide a silo unloader having a wheeled frame supporting a source of power which has connected therein drive means for rotating said wheeled frame 'on'the upper surface of a quantity of packed ensilage within the silo.

Still another object is to provide an unloading mechanism for unloading ensilage'from a silo, said mechanism including an auger arranged to circumferentially rotateand remove ensilage from the top surface of an ensilage pile.

Another object is to provide a'silo unloader including a circumferentially rotatable ensilage scraper mechanism arranged to remove. ensilage 9 Claims. (Cl. 222-254) and carry the same to an elevating means centrally positioned within the silo.

Another object is to provide'an ensila e ele vating mechanism including a stationary tubular member having a pair of helical blades rotatable therein, said blades being positioned in vertical spaced relation.

A still further object is to provide a silo un-.

loader having a spidershapedfirame arranged to circumferentially "rotate within a" silo, "said 2 :frame including wheels arranged to be-driven from a power source mounted on a stationary pp t I A still further object is to 'provide a silo un loading mechanism including an auger for removing ensilage, said auger being circumferentially rotatable within'a cylindrical'silo and including means for retaining said-auger on ahorizontal level working position.

Another object is to 5 provide an ensilage unloader, said unloader including a rotatable scraper mechanism having a, leveling mean connected thereto for retaining said scrapermechanism in a level rotating position." These and other objects will become more clearly apparent from a reading'of the annexed specification when examined in conjunction with the accompanying drawings.

In the drawings: a Figure. 1 is a sectional view through the upper end of a conventional type silo, said'section, showing in elevation, an ensilage unloading mechanism.

Figure 2 is a plan view of the ensilage'unloading mechanism.

Figure 3 is an enlarged elevational view of a portion of the ensilage mechanism, said view showing portions of the driving means.

Figure 4 is a detail view'tak'en'along the line 4-4 of Figure 3 showing a; portion of the driving mechanism for the ensilage. unloader.

Figure 5 is a plan view taken along. the line 55 of Figure 1', said view showing a driving arrangement for a wheel or an ensilage unloader.

Figure 6 is a sectional view taken along the line 66 of Figure 5. L

Figure 7 is a sectional view through a centrally positioned stationary supporting member andele- V vating conveyor of an ensilage unloader.

Figure 8 is a side elevational view through a portion of a silo showing a'portion of a modified ensilage unloading mechanism said mechanism.

including a leveling unit for keeping the auger' I generally designated by thereferencel character.

l0. The silo [0 includes a cylindrical vertical wall I lhaving a quantity of ensilage A packed therein in a conventional manner; The silo 10' is provided with a vertically extending slot l2 extendmg the'full lengthofthecylindricalwall ll;

The slot I2 is provided with a plurality of equally spaced transversely extending beams l3 which serve to rigidly secure the walls of the silo. The structure of the silo is usually of concrete, but may be of any suitable type of building material. A plurality of doors l4 extend vertically upwardly in spaced relation within the vertical slot l2. These doors are supported by i the transverse beams l3 and may be readily removed for the purpose of removing ensilage.

The frame structure A silo unloading device or structure is generally designated by the reference character 5. The unloading device I5 includes a stationary vertical support which comprises an upper tubular section l6 and a lower tubular sectionl'l as best shown in Figure '7. The lower tubular section ll is provided with a cylindrical inner wall l9 having an undercut portion 20. The upper tubular section l6 fits into this undercut portion 20 in telescoping relation and is rigidly secured therein.

A rotating frame structure of spider shape is designated at 2|. The frame structure is arranged to rotate vertically about the stationary support H5. A plurality of tubular frame members 22 extend radially outwardly from a central hub or collar portion 23. The collar portion 23 is provided with an annular groove 24 which is in alinement with an annular groove 25 in the lower tubular section 18. A plurality of ball bearings are journaled within this groove and in this manner an effective bearing construction is provided.

The ends of the tubular members 22 have connected thereto supporting wheels 21 and drive wheel 28. As best shown in Figures 5 and 6, a sleeve or collar 29 is j'ournaled on the end of a framemember 22. The collar 29 is rigidly secured to a U-shaped bracket 3|]. A bracket 3|, comprising a pair of parallel spaced side plates 32 and an end plate 33 is rigidly secured to the U- shapedbracket 30. An upwardly extending arm 34 on one of the side plates 32 has connected thereto a shaft35. A shaft 36 is also supported on and between the side plates 32. The forward ends of the bracket 3| support an axle 31 on which the wheel 28 is journaled.

The ensilagegathering mechanism and conveying mechanism Asbest shown in Figures 1 and 2, an auger 40 is positioned beneath the frame 2|. The auger 49 includes a horizontally extending helical blade 4| which is rotatable on a forward strap 42 and on a rear strap 43.

As best shown in Figure 7, a vertical conveyor or auger 45includes an upper helical blade 46 and a lower helical blade 41. The blades 46 and 41 are rotatable about a vertical axis within the stationary tubular supporting member IS. A plate 48 closes the upper end of the supporting member I6. As best shown in Figure 7 the upper tubular section I6 is provided with an opening 49 which is in communication with a movable elevating type of conveyor generally designated by the reference character 50.

The conveyor '50 includes an angularly positioned sheet metal trough 5| which is rigidly supported on a box enclosure 52 secured to the stationary supporting member l6. An endless chain 53 is centrally positioned within the trough 5| and is trained around an upper sprocket 54 and a lower sprocket 55. The chain carries for movement therewith a plurality of shovels 56 for elevating ensilage within the conveyor trough.

The driving mechanism 7 drive pulley 62 rotates a belt 63 which in turn is connected to a pulleyor sheave 64 which in turn is rigidlynsecured vtoa shaft extension 65. The shaft extension 65 extends downwardly through the plate 48 into the stationary support l6 where in turn it is "rigidly secured in any conventional ,mannerto the auger 45. The shaft is also supported by means of a bracket 66. A sprocket 61 is connected to the shaft 5| immediately below the pulley 54. r A chain 68 is connected to the sprocket 61 and isdriven thereby, said chain extending about a sprocket 6 9 rigidly secured to a shaft 70 as best showniin Figure 3. The vertical shaft 10 is supported in parallel relation to the supporting inember l6 'by means of a pair of brackets H.

A flexible shaft mechanism 12, of conventional design, is connected to 'thehpper end of the shaft 10, the outer casing of said mechanism being supported by means of a bracket 13. The flexible shaft mechanism 12 includes the usual internal driving member or shaft not shown in the present disclosure. The flexible shaft mechanism 12 "is connected to the upper sprocket 54 for driving the endless chain '53.

The lower end of theshaft'lu has connected thereto a pulley which in turn is arranged to drive a belt 15. The belt 15 is in driving engagement with a driving member 76, said driving member 16 including a pair of pulley members 16'. As best shown in Figure 7, the pulley members 78 are' rotatable about the vertical support |6 by means of a pluralityof ball bearings 11. A belt 18 is connected and driven by the lower pulley 16 'of the driving member 16. The belt 18 is trained about an idler pulley l9 and is connected to a pulley 80 which is rigidly secured to a shaft extension 8| connected to drive the auger 45.

The cheer the shaft extension 8| is' provided with a sprocket 83 which is arranged to drive a chain 84 trained about a comparatively large drive sprocket 85. The sprocket 85 rotates a horizontally extending shaft'86 which by means of a universal joint 81 is cohnected to an angularly positioned shaft 88. "The shaft 88 is connected by means of a universal joint 89 to the shaft 36 positioned and carried by the bracket 3|. The shaft 36 has mounted for rotation thereon a sprocket 90 which is arranged to drive a chain 9|. The chain 9| 'is trained about an idler sprocket 92 carried by the shaft 35. A sprocket 93 is drivenby the chain 9|, said sprocket being rotated (in the shaft 31 and arranged to drive the drive wheel 28. 7

As best shown in Figures 1 and '2, a guide wheel 96 is positioned above the auger 40, said guide wheel being arranged to ride upon the inner surfaces of the cylindrical wall of the silo during rotation of the frame 2|.

The auger leveling means The auger leveling meansis designated by the reference character |00 "as shown in Figures '8,

9 and 10. The leveling means I includes a bracket IOI which is rigidly secured to the vertical supportingstructure I6 and extends radially outwardly therefrom. The bracket I M supports 6 about its own axis, the" helical blade 4'! 'is ef-' fective to remove and scrape of]? portions from the top surface of the ensilage A. .The ensilagev t which is thus removed is conveyed inwardly toa pendulum I02 having a weighted enlarged 5 ward the vertical, conveyor or auger 45.. The bearing portion I03. The pendulum is pivotally auger 45 is effective toliftf the ensilage'vertically connected to the bracket IOI as indicated at within the tubular support I6 up to the opening I04. H 49. The ensilage is forced through the opening A driving member I05 is journaled for vertical 49 into the trough 5I of. the conveyor 50. The rotation about the support I 6., Thi driving mere--10 endless chain 53and the. shovels: rfifisc'ause. the her is similar in construction to the driving memensilage to be carried up-the trough-and disber I6 shown in Figure 3. The driving member charged outwardly of the silo. This process I05 has a pair of inner rotating surfaces I06, continues until sufficientensilage has been rethe purposes of which will presently become more moved, whereupon the motor is shut. err and apparent. the remover comes to rest. ontop of the en- A shaft I0! is journaled for rotation withinsilage. the bearing member I03 by meansof a,plura 1ity As best shown in. Figure '7, the vertical auger of bearings I08. The thrust collars I09 arerpros5 consists of an upperiandlower helical blade. vided on the shaft I01 for retaining-thesame The vertical spaced relation of these blades'iswithin the bearing member I03. of exceptional importance in a silo unloading A frictiondrivememberg 1 I 0. is ponnected to device of this type. During the operation them the., eI,1.d of the shaft I 01,.; This.. member may v husks of corn tendto becomewedged between preferablybe made of rubber tosecure positive the peripheral edge of the helical blades and driving engagement. withtthe surfaces 1.105 as the inner wall of the-tubular support. -I-f a willpresently be described. The shaft; {-91 is consingle blade is utilized, thesehusks: are-slowly nected by means of a universal joint to ;an angu-- carried up into the upper-portion-ofthe tubular--- lar, shaft III. The angulanshaft III is com support and as more of these husks becomenected by means :of. a .universal joint to a stub wedged between the wallsand theeaugerg :the shaft H2 suitably journaled in, a supporting friction becomes sufficientlygreat to--finally-com---=-' standard I I3 rigidly. securedto one of-.;the frame pletely clog up the operation. It is therefore demembers 22... The .end ofthe stub shaft 2 has sirable to provide a pair -of---=vertieally- -spaced thereon a spline member U4. The spline member helical blades. Thus, if the corn-husky become- II 4 is in driving engagement with a gear H5. wedged between the blade and inner surface As best shown .in Figure.,l0..the gear [IS inof the tubular structure,-they"-'are=' carried "upcludes a hub portion. I16 whichextends through wardly onlyas far as the upper-end-of the' lowe r and is rotatable .within an vopening ljl formed blade, where they then--- become"dislodged'and in an arm I I8., A collar II.9 s ecures the gear. again either fall to the-lower endof the-tubular 5 011 the arm II 8, I structure or are carried normally-'upwardly in--- As best shown in Figure. 1-0,, the gear I I5 is wardl on the .blades of the upper auger. In threadedas indicated at I20;,;. The. gearv H5 is 40 otherwords, by separating-.the'bladesit is posthus. threaded upon a screw or threaded meme sible to preventthe corn husksfrom--bei-ng carber I2I connected securely,.to a bracket I22. ried up the full .lengthgofthe .auger -andthu The arm II 8 is rigidly secured to a bell crank jamming the operation... -This arrangement is- I23 which by means of a shaft-J24 .is journaled especially important in that it provides means on the end of one of the supporting frame mem- 5 for preventing cloggingofthezauger during,. p bers 22. A guide. wheel. I26 is connected to the eration. e 1,5,; g. arm II8, said guide wheel. being similarwin con- In a silo unloader of g-thewpresent'.typeewhere struction and function to..the guide wheel t6 the structure is completely-carried on. theen shown in Figure 2. i silage surface proper, it is desirable-that a level:-

ing means be provided toassurehorizontaLposi- 7W... tioning of the auger .atall .times. Durin the-.. Dur n e operation of .the. silo unloading winter months, the silage, of course, in many mechanism I0 the cable 9I. is slackened so that. instances becomes frozen. Thisgenerally.istrue... the wheels 21 and 28 completely support the of the silage which is packed n th north Side, structure on top of thepacked ensilage within of the silo. It can be seen,-therefor.e, that the the silo. As best shownin Figure l. the eleauger would have atendencvtomore effectively vating conveyorI5 is positioned .so that theupper work upon the unfrozen ensilage, thereby (meat-1;... end of the same projects within the slot I2 ing an uneven upper surface; ,This.ordinarily..,- of the silo. The doors I4 are.remo.ved as the would result in tiltingtheframe ,2I, into an an ,v mechanism descends during unloading of the enlar osition, the angle of which, ofcourse, would, silage. The motor 60 is placed into operation become progressivelygreater if no leveling means... and by means of the drive connection previously were provided. .The' leveling mean jen i "deg described the drive wheel 28 engages the ensigned to take care. of this situation, Asthe silage and starts the frame 2 I rotating in a cirframe 2| tends to forman angledworkingpns w cumferential manner about the stationary sup- ,tion within the silo, the pendulum type of adjust-.. rt, .I5. I ing mechanism is effective to. retain the auger in e Wheels 27 and Z ar t a l., imes in a completely horizontal operatingposition so. engagement with the upper surface of the enthat the angularity, and unevennessof the surface silage and in view of the angular position of of the ensilage is soon corrected .and leveledofi". the wheels they may partially ride upon a por- 7 As the frame assumesan .angled positionethe tion of the inner cylindrical wall; of the silo. pendulum, of course, I02, retains anabsolutely The frame 2I thereupon continues rotatingand vertical position. Dependingjnpon the angle of themotor I50 is also effected to drive. the auger the frame, the friction drivegmember.,ljllmcomes' 40 about its own axis. As the au er 40, 5 rotating into engagement ,witheitherb th inn r u I both bodily and in a circumferentialfashion and ,75 A 05 surfaces I06 of the. .drivingmembe shafts I07, Hi and H2 are thereupon placed into rotation and the spline member I M is effective to rotate the gear H5. As the gear H5 is rotated on the threaded screw I20, the gear H5 is effective to move the arm 1 l8, thus rotating the bellcrank 123 about the shaft [24. As the bell-crank is rotated, the end of the auger 40 is moved vertically to compensate for the angularity of the frame structure itself. The end of the auger is supported in the strap 43 in a pivotal manner so that the forward portion of the same may be thus readily vertically moved. It can be seen, therefore, that upon the slightest angular position of the frame 2! the leveling mechanism is effective to immediately react upon the auger, thus retaining the same in a positively level position. Since this level position is maintained, any angular or uneven portion of the upper surface of the ensilage will soon disappear and the frame therefore again assumes a normal rotating level position. Thus, angularities of the frame are immediately compensated for by the leveling mechanism so that the auger is maintained in a horizontal operating position.

It can now be readily understood that applicant has provided a novel and effective ensilage unloading mechanism which is entirely supported and driven upon the upper surface of a quantity of packed ensilage within a silo. The farm operator therefore need not spend time consuming operations in climbing to the top of the silo and removing ensilage by hand. He simply can press a button or other switch means at the lower end of the silo and start the mechanism in operation. An electric motor may be utilized for this purpose and the switch mechanism and circuits therefore have not been shown since they can be of any conventional type.

In order to assure continued level operation of an unloader of this type, a leveling means has been provided which will effectively maintain the auger and frame in a level position despite irregularities of packing or density of ensilage within the silo.

It is to be understood that modifications or changes may be made which do not depart from the spirit of the invention as disclosed nor as defined in the appended claims.

What is claimed is:

1. For a silo having a cylindrical vertically extending wall structure, a silo unloading device comprising a structure supported entirely on the top surface of packed ensilage within a silo and being free to descend with the level of the ensilage as it is removed from the silo, said structure including a stationary supporting member, a wheeled frame connected to said supporting member for circumferential rotation about a vertical axis, an auger carried by said frame and movable therewith to remove portions from the surface of the packed ensilage, leveling means for retaining said auger in a level circumferential rotating osition comprising an arm pivotally connected to said frame and having a portion thereof connected to said auger, adjustable means connected to said arm including a rotating member rotatable for pivotally moving said arm and for vertically adjusting the auger relative to said frame, a driving member rotatably carried on said stationary supporting member, said driving member having a pair of spaced rotating surfaces, a pendulum pivotally connected to said supporting member, said pendulum being connected to said rotating member and arranged to support said rotating member in a level horizontal position whereby during an angular rotating position of said frame said rotating member engages either of said spaced rotating surfaces of said driving members, whereupon said rotating member is rotated and said arm is pivoted to compensate for the angularity of said frame and said auger is retained in a level operating position.

2. For a silo having a vertically extending cylindrical wall structure, a silo unloading device comprising a structure supported entirely on the top surface of packed ensilage within a silo and being free to descend with the level of the ensilage as it is removed from the silo, said structure including a stationary supporting member, a wheeled frame connected to said supporting member for circumferential rotation about a vertical axis, an auger carried by said frame and movable therewith to remove portions from the surface of the packed ensilage, leveling means for retaining said auger in a level circumferential rotating position comprising a bell crank pivotally connected to said frame and having a portion thereof connected to said auger, said bell crank being pivotally movable for vertically adjusting said auger relative to said frame, adjustable means connected to said bell crank including a rotating member, a driving member rotatably carried on said stationary supporting memher, said driving member having a pair of spaced rotating surfaces, a pendulum pivotally connected to said supporting member, means supporting said rotating member on said pendulum, said pendulum being arranged to support said rotating member in a level horizontal position whereby during an angular rotating position of said frame said rotating member engages either of said spaced rotating surfaces of said driving members, whereupon said rotating member is moved and said bell crank is pivoted to compensate for the angularity of said frame and said auger is retained in a level operating position.

3. For a silo having a cylindrical inner wall, an unloading device comprising a structure supported on the packed ensilage and arranged to move downwardly with respect thereto upon the lowering of the ensilage level, said structure including a stationary supporting member, a spider shaped frame journalled on said supporting member for rotating movement about a vertical axis, said frame including a plurality of radially extending arms, wheels rotatably connected to said arms, said wheels being positioned circumferentially adjacent the cylindrical Wall of said silo and arranged to support said structure on the top surface of said ensilage, means for rotating said frame including, a power unit supported on said stationary supporting member and portable therewith, transmission means connecting said wheels and said power unit, an auger connected to said frame and arranged to rotate circumferentially therewith, drive means connecting said auger and said power unit for operating said auger from said power unit thereby removing portions of said ensilage, and a conveyor arranged to receive said ensilage and discharge the same from said silo.

4. For a silo having a vertically extending cylindrical wall structure, a silo unloading device comprising a structure supported on the top surface of ensilage packed within the silo, said structure including a centrally positioned supporting member, a rotatable frame connected to said supporting member for relative rotation about a vertical axis, said frame including a plurality of radially extending arms rotatable therewith, a wheel rotatably connected to each arm, the wheels being arranged to support said structure on the ensilage within-the silo, a first auger carried-by said frame'and' rotatabletherewith for-gathering ensilage, asecond auger supported by'said structure and extending vertically with respect thereto, a conveyor carried by" said structure, said conveyor having a receiving end in communication with the vertical auger and a discharge end in communcation with the outside of said silo, a power unit carried by said structure and portable therewith, said power unit including first drive means connected to one of said wheels to drive the same thereby circumferentially rotating said rotatable frame and the ensilage gathering auger, second drive means connecting said power unit and said augers for driving said first and second augers for gathering and elevating ensilage to said conveyor, and means for moving said conveyor, thereby effecting discharge of ensilage from the silo.

5. For a silo having a vertically extending cylindrical wall structure, a silo unloading device comprising a structure supported on the top surface of ensilage packed within a silo, said structure including a tubular centrally positioned supporting member, a rotatable frame including a hub portion journaled on said supporting member for relative rotation about a vertical axis, a plurality of radially extending arms connected to and rotatable with said hub portion, a wheel rotatably connected to each arm, the wheels being arranged to support said structure on the ensilage within the silo, a first auger carried by said frame and rotatable therewith for gathering ensilage, said auger having one end adjacent said vertical supporting member and extending radially outwardly therefrom, a second auger rotatable about a vertical axis within the tubular supporting member, a conveyor carried by said structure, said conveyor having a receiving end in communication with the vertical auger and a discharge end in communication with the outside of said silo, a power unit carried by said structure and portable therewith, said power unit including first drive means connected to one of said wheels to drive the same, thereby circumferentially rotating said rotatable frame and the ensilage gathering auger, second drive means connecting said power unit and said augers for driving said first and second augers for gathering and elevating ensilage to said conveyor, and means for moving said conveyor thereby effecting discharge of ensilage from the silo.

6. For a silo having a vertically extending wall structure, a silo unloading device comprising a structure supported on the top surface of ensilage packed within a silo, means for lowering and raising said structure, said structure including a vertical supporting member, a rotatable frame including a hub portion connected to said supporting member for relative rotation about a vertical axis, a plurality of radially extending arms connected to and rotatable with said hub portion, a wheel rotatably connected to each arm, the wheels being arranged to support said structure on the ensilage within the silo, a first auger carried by said frame and rotatable therewith for gathering ensilage, said auger having one end adjacent said vertical supporting member and extending radially outwardly therefrom, a second auger supported by said structure and extending vertically with respect thereto, a conveyor carried by said structure, saidconveyor having a receiving end in communication with the-vertical auger and adischarge end in communication with the outside of said silo, a power unit carried by said structure and being portable therewith, said power unit including a first drive means connected to one of said wheels to 'drive' the same thereby circumferentially rotating said rotatable frame and the first auger, second drive means in the silo, a flexible element connected to the frame'structure and adapted to be supported on an upper portion of the silo, the flexible element being movable for raising and lowering the unloading device within the silo, a centrally positioned vertical tubular support on said frame structure, a rotatable frame journalled on said support for rotating movement about a vertical axis, a plurality of wheels connected to the rotatable frame structure for supporting the unloading device on the upper surface of packed ensilage within the silo, a material gathering scraper member connected to and movable with said rotatable frame, said scraper member including means for conveying ensilage to said tubular support, an elevating mechanism within said tubular support, a conveyor supported on the frame structure, said conveyor being positioned to receive ensilage from said elevating mechanism and to discharge the same from the silo, a power unit supported on and portable with said frame structure, and a driving connection between said power unit and one of said wheels to provide traction'for said wheel with respect to the packed ensilage and for rotating said rotatable frame with respect to said frame structure.

8. A silo unloading device for a silo in accordance with claim 7, the elevating mechanism within said tubular support including a first helical blade disposed for rotation within the tubular support, said helical blade terminating at its lower end in vertically spaced relation from the lower end of said tubular support, a second helical blade on the elevating mechanism, said second helical blade having its upper end spaced from the first helical blade and its lower end projecting downwardly and outwardly from the tubular support, and a drive element connected to the power unit and the elevating mechanism for rotating said helical blades.

9. For a silo having an inner vertically extending cylindrical wall structure, a silo unloading device including a frame structure supported within the silo, a flexible element connected to the frame structure and adapted to be supported on an upper portion of the silo, the flexible element being movable for raising and lowering the unloading device within the silo, a rotatable frame journalled on said support for rotating movement about a vertical axis, a plurality of wheels connected to the rotatable frame structure for supporting the unloading device on the upper surface of packed ensilage within the silo, a material gathering scraper member connected to and movable with said rotatable frame, said scraper member including means for conveying ensilage toward the axis of said rotatable frame,

conveyor means supported on the frame structure, said conveyor being positioned to receive ensilage from said scraper members and to discharge the same from the silo, a power unit supported on and portable with said frame structure, and a driving connection between said power unit and one of said wheels to provide traction for said wheel with respect to the packed ensilage and for rotating said rotatable frame with respect to said frame structure.

WALTER R. PETERSON.

References Cited inthe file oi this patent UNITED: STATES PATENTS Number Name Date Keys Jan. 8, 1924 Foster Aug. 18, 1925 Vali et a1 Oct. 13, 1936 Olson Aug. 29, 1944 Cordis July 13, 1948 Cordis Aug. 15, 1950 

